Epilepsy seizures can range from something as subtle as a passing localized numbness to something as noticeable and potentially dangerous as wild involuntary thrashing. While some people experience symptoms before a seizure that indicate one is about to occur, others have no warning at all. A new device designed to be implanted between the skull and the brain surface has been found to accurately predict epilepsy seizures in humans and can indicate the risk of a seizure occurring in the coming hours.

The small neurological implant was developed by Seattle-based NeuroVista Corporation, with the first patient implanted with the device in 2010 in Melbourne, Australia, by a team led by Dr. Mark Cook. The implant, which monitors long-term electrical signals (EEG) in the brain, works in conjunction with a second device implanted in the patient’s chest that transmits signals recorded from the brain to a hand-held device.

The hand-held device shows the likelihood of having a seizure in the next few hours by way of a series of lights – red indicates a high likelihood, white a moderate chance, and blue a low likelihood.

A two-year study of the system carried out by Professor Cook and his team included 15 epilepsy sufferers aged between the ages of 20 and 62. These subjects experienced between two and 12 seizures a month and hadn’t had their seizures controlled with existing treatments.

To allow the team to develop individual algorithms to predict seizures for each patient, for the first month of the trial the system was set purely to record EEG data.

The system was found to correctly predict high warning seizures 65 percent of the time, with a level better than 50 percent seen in 11 of the 15 patients. Of these 11, eight had their seizures accurately predicted between 56 and 100 percent of the time.

“One to two percent of the population have chronic epilepsy and up to 10 percent of people will have a seizure at some point in their lives, so it’s very common," said Professor Cook. "It’s debilitating because it affects young people predominantly and it affects them often across their entire lifespan."

“The problem is that people with epilepsy are, for the most part, otherwise extremely well,” he added. “So their activities are limited entirely by this condition, which might affect only a few minutes of every year of their life, and yet have catastrophic consequences like falls, burns and drowning.”

Professor Cook and his team aim to continue with larger clinical trials in the hope that the technology will lead to improved management strategies for epilepsy. NeuroVista hopes the early detection of impending seizures could lead to the development of fast-acting drug therapies to prevent the seizures occurring.